This is great for situations where your Raspberry Pi doesn't have any other internet access. But if you do have and ethernet drop or Wi-Fi you can also use your carrier's email to SMS gateway!
As long as it isn't critical that your carrier's gateway is operating normally.
I have a customer that routinely emails through various carier's SMS gateways, and has reports several times a month that their messages aren't getting through and ask us to verify everything was handed off correctly. It always was handed off good, but their gateway is backlogged or broken for that half day or day.
This echos my direct experience years ago (before I made my own solution similar to this setup).
For example "[YOUR-PHONE-NUMBER]@txt.att.net"
https://www.dialmycalls.com/blog/send-text-messages-email-ad...